Improvement in sewing-machine



`2 SheetsSheet 1. D. MACPHERSON.

Sewing Machine.

Patented lune 29, 1869.

Jay 146.

2 Sheets-Sheet 2.1

D. MACPHERSON. Sewing Machine.

Patented J une 29, 1869.

dltitrtl gaat@ @thanl dipinte.

Letal-s Paten Iv .92,068, dated .new 29, 1869 IMPROVEMENT IN SEWING-MACHINE.

The Schedule referred to in these Letters Patent and making part of the same.

` To all whom tt may concern..-

Be it known that I, DANIEL MAoPHaRsoN, of Edinburgh, North Britain, have invented certain Improvements in Sewing-Machines; vand I do hereby declare the following to be a full, clear, and exact description ofthe saine. l

My said invention relates to what are generally known as lock-stitch sewing-machines, and consists in the construction and use ot' a shuttle having the general form of the frustum ot' a cone, provided with a space within it, for holding a bobbin, and receiving a rotarvxnotion on its own axis, whereby the said shuttle and the included bobbin are made to pass through the loop in the upper thread, and thereby produce that kind ot' stitch known as the lock-stitch, the action ot' this shuttle being such as to takeup the slack ot' the upper thread, and thus to supersede the use ot' springs, levers, or other such contrivances, for this purpose; and in order that the said invention may be i'ully understood, I shall now proceed more mrtieularly to describe the saine, and for that purpose shall refer to the several Iigures on the annexed sheets ot'drawiugs, the saine letters ot' reference indicating corresponding parts in all the correspoiuling tigures.

This peculiar' shuttle is represented by tigs. l, 2, and 3,1m sheet l ot' the accompanying drawings.

Figure l is a front elevation of the shuttle;

Figure 2 is a back elevation; and

Figure 3 is a section of the shuttle, taken through its axis.

The outline of the shuttle is nearly an entire circle, as seen in tigs.1 and 2. The back is tlat, or nearlyso, and the front is protuberant, as seen in the section, lig. 3, or in the profile or edge view, Figure 5, so that the shuttle has the generalappearance of the frustunl of a cone. y

Apart of the circumference is cut away between the points A and B,and is hollowed out, so as to form a notch or recess, A C B, to receive and carry round `the loop in the upper thread.

The sides of this recess are rounded, so as to make, at A, a moderat-ely sharp point, which is the toe ofthe shuttle, and at B a'bluntish end, which is the heel.

The surface ot' this notch, and the whole external surface ot' the shuttle with which the threads may come iu contact, are carefully smoothed,'and the edges blunted, in order that the threads may glide easily over them without damage.

The sloped part of the protuberance may be conical, as shown in the section, tig. 3, and profile, fig. 5, or it may have a curved outline. I prefer the conical form, as being easily' made.

In the protuberant part of the shuttle, a cylindrical or slightly-conical cavity, D D, is made, for receiving the bobbiu ou which the under thread is wound.

This cavity is not made entirely through the shuttle, but a plate is left, suticiently stron gto carry a centre-pin, EE, onwhich the bobbin is to turn. By this piuthe bcbbin is kept more steadily than if it were iliade to rest entirely ou the bottom of the cavity, and on its cylindrical sides.

Around the outer edge of this cavity, a lip or ridge, F F, is formed, so as to produce a circular notch, for retaining, until the proper time, the loop that has been made in the upper thread.

A portion, G G, ot' this lip or ridge is removed, for the purpose of releasing the loop at the desired instant.

The bobbin which I use along with this shuttle is shown in section in fig. 4. It is provided with a ceutral hole, to tit and turn easily upon the pin E E.

The back, I I', is made flat, or nearly so, and of a diameter slightly less than that of the bottom of the cavity D D. l

The front J J is made so much less in diameter than the mouth ot' the cavit D D as to ermit the lower l thread, which is wound on the bobbin, to pass easily out between them, and its edgesas well as the outer edge of the cavity D D, are rounded, so as not to cut the thread.

.The front of the bobbin is made convex at the part marked K K1 and the height of the bobbin, from I to J, is made somewhat less than the depth ofthe cavity D D, in ord'er that the edgeJ may be within the plane F F, while the convex part K, as shown in the profile, fig. 5, protrudes a little beyond it. In this way the loop in the upper thread is prevented from slipping into the bobbin.

In fig. 5 the under thread is represented, by a blue line,- as proceeding from the bobbin to the cloth, while the loop of the upper thread, represented by a red liuc, is shown as passing round the circular notch formed by the lip F.

At the upper part, G, of the same tig. 5', the lip is shown as partly cut away.

lhe action of this shuttle is as follows;

It is made to turn on its own axis, once comple-te stroke ofthe needle, its outer edge being brought close to the line ot' motion ofthe needle, and the' two motions, viz, the rotary motion of the shuttle and the reciprocating motion of the needle, are so timed to each other, as that just after the needle has begun to ascend, and has thereby slackened the thread, the toe A comesn-ward, and, passing between the needle and the now slackened thread, takes up the loop.

I prefer to arrange the machine so that the needle may pass close along the back ofthe shuttle, as shown in iig. 5, in which the toeAis representedas having `inst entered the loop. Fig. l shows this position of the shuttle, as seen from the front. v

As the shuttle turns round, the loop is drawn out by the notch A G B, as shown in Figure 6, and is eventually lodged in the circular notch formed by the lip F for each F. This .s shown in Figure T, which shows the shuttle as turned rather more than halt' round from its first position. The upper thread is there shown as held by the lip F F, and as proceeding, through the notch A C B, to the back oi" the shuttle, making its appearance again at the upper edge. If the lip F F were continuons, the loop would be permanently held byit.

Figure 8 shows the position of the shuttle, after having made about tive-sixths of a revolution.4

The needle has now descended, so as again to enter the cloth, which, in the mean time, has been moved forward by the feeding-apparatus, and the upperthread is still held by the lip F F and by the notch A C B.

Figure 9 shows the upper thread, as just about to be relieved from the heel B ot' the shuttle, and the needle as having now descended to its lowest position. The loop is still held by the lip F F. Y

Figure l() shows the loop as disengaged from the heel of the shuttle, and as held only by the lip F F. It is about to be released at the point G, and the toe A is just about to enter the second loop, which. is beginning to he opened by the ascent of the needle.

` Figure 11 shows the shuttle in the same position as in tig. l, that is, after having made a complete revolution. The former loop is now disengaged from the lip F F, and has passed over, so as to enclose the under thread. At the same time., the toe of the shuttle has taken up the second loop, the subsequent forma ltion of which draws up the tirst loop, and thus completes a stitch, havingthe umlcr thread locked into it.

Figure 12 shows the shuttle after the s ccond loop has been formed, and the first loop considerably drawn up.

In this way, at each revolution, the shuttle and the included bobbin maybe said to pass through the loop, or the loop may be said to be passed round them. The formation of the third loop takes up the slack of the second, and thus the sewing goes on.

In order to insure a proper performance of these operations, it is necessary that the sh little be guided steadily, so that the toe A may pass close to the needie, and at the same time, that the guiding-apparatus may not interfere with the threads.

Various guides may be contrived, but I shall only describe two as good examples, being both simple, easily constructed, effective, and convenient.

The tiiLst of these methods ot' guiding the shuttle is represented in tigs. 1, 3, 5, to 13, inclusive.`

Round the outer edge of the shuttle a narrow fillet, H H, is formed, having a tiat surface toward the point. This tillet is sloped away near A, the toe of the shuttle, and is rounded ofi' at the heel B.

ln a plate, L L, -Figure 13, whichmay either' be attached to the trame, or may bca part of the frame of the sewing-machine, acircnlar cavity is tbrmed, somewhat less in'diametcr than the outer diameter of the shuttle, and a circular ht-.d or socket is made round the edge of it, into which the shuttle may tit, the depth of' the bed or socket being sucli, that the tlat surface oi' the fillet H may be justvtlush-with the surface of the. plate L L. r)This bed is shown at M P N, fig. 13.

At the side next to the'needle, a part of the plate L L is eut away, so as to leave an opening, M N, for the working of the needle and threads.

When the shuttle has been placed in this bed or socket, it is retained there by means of the shuttlecover Q Q, which is a movable plate, having a hole exactly the counterpart of that which is formed in the plate L L.

For the sake of easy removal, I attach the shuttlelcover to the plate L L, hy means ot' a hinge, and secure it, when closed, by means of a slot and button, vas shown in iig. 13; but many other arrangements for kei-ping the shuttle-cover in its place may be contrived.

Thefparticular arrangement which may be used for this purpose is not essential to the action of my shuttle. The bed or socket and the shuttle-cover must be so adjusted as that the shuttle may turn easily, without having any unnecessary shake; and it is advisable to make the openings at N N no wider than is actually needed for the ti'cedom of the threads, in order that there may be as much guiding-suriiice as possible.

The shuttle-cover Q Q is shown closed upon thc shuttle in Figure 14, and also in Figure 15, sheet 2; in the former, in section; in the latter, in side elevation.

When the shuttle-cover is closed, all the prot-uberant surface of the shuttle, and also all the outer surface of the bobbin, are exposed toI view, so that the whole process of forming and disengtiging the loop, as already explained, may be seen. i

I find this first arrangement to be very convenient. .It has, however, two disadvantages: tirst, that the oil employed to lnbricate the parts is apt to soil the thread, if the parts be over-oiled; second, that, in the course of use, the shuttle becomes somewhat loose in the socket.

I have obviated the first disadvantage by removing an extremely minute portion of metal from around the edge of the back ot' the shuttle. The abstract-ion ot' this thin portion removesthe point of the toc to a little distance-say one three-humlredth part of an inchfrom the needle. It is, therefore, necessary to bend the toc back to the. general plane, sothat it may come close to the needle. 'ihese small details are too minute, however, to be shown in any drawing.

rlhe second method of guiding the shuttle is shown in Figures 16, 17, and 18, sheet 2.

A V- shaped notch, h., iig. 17, is made around the edge of the shuttle.

This notch cannot be seen when the shuttle 'is viewed from the front, nor from the back, excepting near the toe. and the heel, where the sloping of the surface brings it into view.

This notch h receives the edges of a circular cavity, m n p, tig. 18, formed by the junction of the two hohling-plates q q and q q'.

These plates v:ire sector-jointed on the pin x, at their lower edge, so that they may be opened, to receive the Shuttle, and then closed, to retain it. l

The centre-pin a',.ot' the sector-joint, is screwed into the plate L, ot'tig. 15; and the holding-plates are kept in their places by clamping-screws passing through notches in the holding-plates.

This second arrangement is free from both the disadvantages of the first.. \Vhen the shuttle wears, the holding-plates can be closed upon it, so as to hohl it with any required degree of tightness, and, at thc same time, the oiled surface is out of reach ofthe thread. It has also thisv advantage, that the opening at m 1t may be made smaller than when the shuttlecover is used. Y

rEhetension of' the upper thread may be regulated by any ofthe contrivances for that purpose already in use. The under thread may receive. its proper tension by means ofa washer bound by a screw entering into the pin E E, on which the .hobbin turns, this washer bearing upon the outer surface of the bohbin. '.lhis is, perhaps, the simplest arrangement; butV it has two inconveniences, which are., tirst, that the taking out aml replacing of the hobbin are troublesome; second, that the tension on the under thread cannot be changed without stopping the machine. y

In order to avoid both of these incom'cniences, I cause a thin spring, It It., tigs. 14, 15, 1,8, `attached to the shuttle-cover Q, or to one. of the holding-plates q', to press against the convex part, K, ot' the outer face of the bobbin; and I regulate the pressure of this s ,ring b means of a thumb-screw S.

This thumbscrew S can be used when the machine is in motion andthe removal of the bobbin is effected by opening the shuttle cover Q, or by throwing back that one ofthe holding-plates to which the regulatingspring It is attached.

At each stitch, the loop is drawn through between the spring R and the con'vex'part, K, of the bobbin. This spring thus assists in keeping back the loose loop after it has been disengaged from the part G, and allows it to be drawn gently forward as the next loop is formed.

Thus, what at rst feared would have been an inconvenience, is found to be a great improvement in the action, by preventing the entanglement of the loose loop.

The shuttle and the lbobbin may be made of any suitable material, and of separate pieces, joined together, or each of one piece. l prefer to make them both ot' cast-steel.

Having shown that my shuttle, with its included bobbin, may be so held and guided as that it may be v susceptible of' the required rotary lnotion,'.without the threads heilig interfered with, I shall now proceed toexplain how that rotatory motion may be communicated to it.

The rotatory motion may be obtained from a toothed wheel, ff, Figure 20, turning on an axis, 'n n., inclined to the axis E E ot' the shuttle, and working on internal teeth g y, formed lwithin the body of the shuttle.

The depth ofthe teeth must, in this case, be so-arranged as that the tooth on the one side ofthe notch A l5 C be not released until the tooth on the other side has-be en caught hold of.

The reciprocating motion may be given to the needle iu'any of the ways already in use. I prefer the simplest reciprocating mot-ion, obtained by means of a crank-pin, or an eccentric-wheel, tixed to a revolving axis, which I prefer to be the axis U U, that gives motion to the shuttle. The tension of the upper thread may be obtained in any of the usual ways, and so also the feed and the length of the stitch. These form no part of my invention.

The advantages of my system over the methods for forming the lock-stitch already known are these:

The action is so simple as to he easily understood, while the whole operation is open to inspection.

The drawing up of the loop of the precedingstitch by means of levers or springs is superseded.

There is no occasion for stopping the needle until the shuttle has passed through the loop.

The lip which retains the loop, and keeps the thread ont oi' reach of the toe, being a rigid substance,rthe

machine can at once be made to suit heavy or light work, within the range of its capability, by means of the screws for regulating the tensions ofthe two threads.

The tension of the under thread can be altered, while the machine is working, by means of a thumbscrew placed quite conveniently to the operator.

Neither the upper nor the under thread is twisted; and, while the machine may be worked with very great rapidity, it may also be moved as leisurely as may Vbe desired. I

I claim as my invention, and desire to secure by Letters Patent- 1. The 4conical shuttle, having a lip, F, recess D, and central pin E, for supporting a detachable. spool, all constructed as described. v

2. The combination, with the conical shuttle, of the hinged plates q q', with their curved V- shaped edges adapted to the recess, h, of the shuttle, as and for the purpose speeitied.

3L The combination, with the conical shuttle, constructed as described, of the spring R and set-screw S, when the spring is arranged and hears upon the shuttle, so as to rst detain and then release the loose loop of thread, as set forth.

In' testimony whereof, I have signed my name to this specification, in the presence of two subscribing witnesses.

DANIEL MAOPHERSON.

Vitnesses ,EDWARD Sane, Y ALEXANDER V MORRISON. 

